|Year : 2016 | Volume
| Issue : 1 | Page : 33-35
Coronary artery anomaly: Rare and anomalous branching of left coronary artery
Department of Cardiology, Sree Uthram Thirunal Royal Hospital, Trivandrum, Kerala, India
|Date of Web Publication||4-Mar-2016|
Department of Cardiology, Sree Uthram Thirunal Royal Hospital, Ulloor, Medical College (PO), Trivandrum - 695 011, Kerala
Source of Support: None, Conflict of Interest: None
Coronary artery anomalies are rare, but still rarer is anomalous branching pattern of the left coronary artery (LCA) alone, without any congenital anomalies. We report the case of a 50-year-old man who presented with dyspnea on exertion New York Heart Association (NYHA) class II, had a positive stress test, and his coronaryangiogram revealed the left main coronary artery (LMCA) dividing into four branches. This type of branching pattern is quite rare. He had type I dual left anterior descending (LAD) artery in addition to a fairly large ramus intermedius (RI) and a nondominant left circumflex (LCx) arising from the LCA. Awareness and recognition of dual LAD is of importance to surgeons and interventionalists alike in planning the revascularization strategy.
Keywords: Anomalous branching, coronary arteries, dual left anterior descending (LAD) artery
|How to cite this article:|
Soman B. Coronary artery anomaly: Rare and anomalous branching of left coronary artery. Heart India 2016;4:33-5
| Introduction|| |
Coronary artery anomalies are rare and are seen in approximately 1.3% of patients undergoing coronary arteriography., Variations in origin, course, and distribution of coronary artery are more common in the right coronary artery (RCA)., According to Morettin, 1% of his cases had demonstrated either complete duplication of a coronary artery or one of its branches. Spindola-Franco et al., reported that about 1% of patients with normal heart had dual left anterior descending (LAD) artery (also called dual anterior interventricular artery) in otherwise normal hearts.
We report here a case of a 50-year-old man whose coronary angiogram revealed the left main coronary artery (LMCA) dividing into four branches. This type of branching pattern is quite rare and is of importance to both the surgeons and the interventionalists in planning the revascularization strategy.
| Case Report|| |
A 50-year-old male presented to us with complaints of excertional dyspnea New York Heart Association (NYHA) class II and recent worsening of symptoms, and was diagnosed as having unstable angina. He was a long-standing hypertensive and diabetic controlled on beta-blockers and oral hypoglycemic agents. He had had nephrectomy done in 1992 and also had an anterior wall myocardial infarction in 2002; he also had a family history of coronary artery disease (CAD). His electrocardiogram (ECG) did not show any ST-T changes. His exercise stress test was positive for provocable ischemia. Two-dimensional echocardiography showed concentric left ventricular hypertrophy and regional wall motion abnormality consistent with old anterior wall myocardial infarction. Routine blood investigations were normal. Because of worsening symptoms and positive stress test, the patient was taken up for coronary angiography. The left coronary artery (LCA) angiogram showed the LMCA dividing into four branches: two LAD coronary arteries, a fairly large ramus intermedius, and a nondominant left circumflex artery (LCx) arising from the LMCA. The first and small LAD was short and terminated prematurely in the anterior interventricular sulcus (AIVS), after giving out septal branches. The second branch, which had total occlusion after giving out an early diagonal branch, had delayed filling of the distal vessel through homocollaterals and was running in the AIVS, giving out diagonal branches and terminating at the apex. This was consistent with the type I variety of dual LAD as per the Spindola-Franco classification, a rare entity.
Selective RCA angiography showed dominant RCA, which had multiple significant stenosis in the proximal segment.
The patient was discharged with advice to undergo coronary artery bypass graft (CABG) surgery, as he had significant lesions in all the major vessels.
| Discussion|| |
Based on the origin and course of the long LAD, anomalous dual LAD have been classified into six different types. In addition to the existing classification, Bolzar et al. in a recent series described three more subtypes (type 7, type 8, and type 9), of which type 9 was named as “triple LAD” anomaly, as there were three different vessels in the AIVS.
Dual LAD may be associated with congenital heart disease as the tetralogy of Fallot and transposition of great arteries, where it has surgical importance at the time of corrective surgery. The dual LAD coronary anomaly consists of two branches short and long that supply the usual distribution of the LAD. While the short LAD terminates in the proximal aspect of the AIVS, the long LAD has a variable course outside the AIVS and returns to the inside distally.
Classification of dual LAD 
Type I: Short and long LAD runs in AIVS, long LAD then runs epicardially on the left ventricular side of AIVS, then reenters the distal AIVS and reaches the apex.
Type II: Short LAD is same as in type I, long LAD runs on the right ventricular side of AIVS to reenter AIVS.
Type III: Short LAD is same as in types I and II. Long LAD travels intramyocardially in the ventricular septum.
Type IV: Short LAD forms a very short vessel, travels in the AIVS, and gives off septal perforators and diagonal branches. Long LAD arises from the RCA or right sinus of valsalva, courses anteriorly to the infundibulum of the right ventricle, and turns sharply down the AIVS to give out septal and diagonal branches.
Type V: Short LAD arises from the left coronary sinus. Long LAD originates from the right coronary sinus and has an intramyocardial course within the septal crest, emerging epicardially in the distal AIVG, and gives out the septal and diagonal branches.
Type VI: Short LAD from the LMCA and gives off septal and diagonal branches. Long LAD arises from the proximal RCA with the epicardial course between the right ventricular outflow tract (RVOT) and the aortic root, continuing to the mid- or distal AIVG, and gives out diagonal branches.
It is important for cardiologists to be aware of this anomaly when interpreting the coronary angiogram of these patients and making decisions regarding management. Awareness and recognition of the dual LAD is vital for planning revascularization of the coronary artery. In our case, the patient had two LADs supplying the anterior wall of the left ventricle. The short LAD originated from the LMCA and terminated prematurely after giving rise to the septal branches [Figure 1]. The long LAD originated from the LCA and had total occlusion after giving out an early diagonal branch and delayed filling distally through homocallaterals, ran in the AIVS, and gave rise to diagonal branches, reaching to the apex, [Figure 2] and [Figure 3] which was suggestive of type I dual LAD, a rare type of coronary anomaly.
|Figure 1: The left anterior oblique (LAO) caudal view of LCA, showing the four branches of LCA: the short LAD (thin white arrow) originating from the LMCA, giving rise to the septal branch, the long LAD (thick white arrow) occluded after a diagonal branch, along with the fairly large RI and a nondominant LCx|
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|Figure 2: The right anterior oblique (RAO) cranial view of LCA, showing short LAD (thin white arrow) originating from the left main coronary artery, giving rise to the septal branch and the long LAD (thick white arrow) occluded after a diagonal branch|
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|Figure 3: The anterior posterior (AP) cranial view of LCA, showing short LAD (thin white arrow) originating from the LMCA, giving rise to the septal branch, and the long LAD (thick white arrow) occluded after a diagonal branch with faint antegrade filling of the distal long LAD through homocollaterals|
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| Conclusion|| |
In conclusion, we report a type I dual LAD coronary artery, which is a rare coronary anomaly.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]